• Journal of Korean Neurosurgical Society
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• v.30 no.sup2
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• pp.281-288
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• 2001

Objectives : The purpose of this study is to evaluate the usefulness of SSEP monitoring during intracranial aneurysm surgery and compare the characteristics of wave change in relation to neurologic changes between ACA aneurysms and MCA aneurysms. Methods : During recent three years(between January 1997 and November 1999), intraoperative SSEP monitoring had been done in 63 operations for intracranial aneurysms. We had monitored the median nerve SSEP during surgery for aneurysms of MCA and the posterior tibial nerve SSEP for aneurysms of ACoA or ACA. A more than 50% reduction of any cortical SEP response was considered to be a significant SEP change, compared to its baseline value before the start of surgery. Changes in the SEPs were categorized as follows : Type IA, no significant amplitude changes without temporary clipping ; Type IB, no significant amplitude changes with temporary clipping ; Type II, significant changes with temporary clipping and complete return to control amplitude ; Type III, significant changes with temporary clipping and incomplete return to control amplitude ; Type IV, significant changes with temporary clipping and more decreased amplitude changes. Results : Among the 63 intraoperative monitoring, there were 37 cases of ACA aneurysms(An), and 26 of MCA An. The temporary proximal arterial occlusion during surgery were performed in 31(83.8%)cases of ACA An, 22(84.6%) of MCA An. Seven of the 31 ACA An(22.6%) and ten of the 22 MCA An(45.5%) had significant changes. The type were as follows : 4 patients with type II and 3 with type III in the ACA An ; 3 patients with type II and 3 with type III and 4 with type IV in the MCA An. In both group type II changes had no new postoperative neurological deficit. All 6 patients with type III had new neurological deficits ; However, One case in the ACA An and two cases in the MCA An. had transient neurologic deficit and improved markedly over the next two months. All 4 type IV changes in the MCA An. had permanant neurologic deficits. Two out of 30 cases(6.7%) in the ACA An. and one out of 16 cases(6.3%) in the MCA An. without significant amplitude change had new neurologic deficit postoperatively. Conclusion : Based on this study, Intraoperative SSEP monitoring during aneurysm surgery would provide useful information for detecting cerebral ischemia. SSEP response during surgery for MCA An. is more sensitive than ACA An. Otherwise, there were no meaningful difference in rate of false negativity.

• Journal of Korean Neurosurgical Society
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• v.46 no.6
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• pp.568-571
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• 2009

Accessory middle cerebral artery (MCA) is an infrequent vascular anomaly of the brain. Cerebral aneurysms associated with this anomalous artery are also very rare. To our knowledge, there have only been ten previous reports of an aneurysm associated with accessory MCA. The authors present two patients with accessory MCA-related aneurysms. A 38-year-old male and a 59-year-old female both presented with sudden-onset severe headache. In both patients, computed tomography (CT) scan revealed subarachnoid hemorrhage. A subsequent angiogram demonstrated an accessory MCA arising from the anterior cerebral artery (ACA) and a saccular aneurysm at the anterior communicating artery (ACoA) complex associated with an accessory MCA. Surgical clipping allowed for complete exclusion of the aneurysm from the arterial circulation. Based on our review of the ten cases of aneurysms associated with accessory MCA documented in the literature, we suggest that accessory MCA-related aneurysms can be classified according to whether the accessory MCA originates from the proximal A1 segment or from the ACoA complex. We also emphasize the importance of precise interpretation of preoperative angiograms and intraoperative precaution in determining the presence of this anomalous artery prior to temporary clip placement.

• Journal of Korean Neurosurgical Society
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• v.59 no.3
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• pp.269-275
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• 2016

Objective : Although middle cerebral artery (MCA) aneurysms are less amenable to coil embolization, an increasing number of studies support favorable endovascular treatment for them. The purpose of this study is to compare the outcomes of two different treatments (surgery versus coiling) and evaluate the benefits of surgical clipping for MCA aneurysms. Methods : Here we retrospectively analyzed the outcomes of 178 ruptured and unruptured MCA aneurysms treated in patients between September 2008 and April 2012. Parameters assessing treatment outcomes include degree of aneurysm occlusion, presence of regrowth, clinical status, and complications. Results : Among 178 MCA aneurysms, 153 were treated surgically. After a mean follow-up of 12 months, the surgery group showed a clinically significant complete occlusion rate (98%) compared with the coiling group (56%) (p<0.001). Follow-up radiologic evaluation showed a higher regrowth rate (four of 16 cases) in the coiling group than in the surgery group (one of 49 cases) (p=0.003). There was no statistically significant difference in favorable clinical outcome rate between the two groups. The procedure-related permanent morbidity and mortality rates were 2% (three of 153 cases) in the surgery group and 0% (0 of 25 cases) in the coiling group. Conclusion : Compared to endovascular treatment, surgical neck clipping for both ruptured and unruptured MCA aneurysms results in a significantly higher complete obliteration rate and less regrowth. Therefore, even in this endovascular era, we still recommend surgical clipping as the primary treatment option for MCA aneurysms rather than coil embolization.

• Journal of Yeungnam Medical Science
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• v.36 no.3
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• pp.208-218
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• 2019

Background: The anatomy of middle cerebral artery (MCA) aneurysms has been noted to be unfavorable for endovascular treatment. The purpose of this study was to assess the feasibility and efficacy of coiling for MCA aneurysms. Methods: From January 2004 to December 2015, 72 MCA aneurysms (38 unruptured and 34 ruptured) in 67 patients were treated with coils. Treatment-related complications, clinical outcomes, and immediate and follow-up angiographic outcomes were retrospectively analyzed. Results: Aneurysms were located at the MCA bifurcation (n=60), 1st segment (M1, n=8), and 2nd segment (M2, n=4). Sixty-nine aneurysms (95.8%) were treated by neck remodeling techniques using multi-catheter (n=44), balloon (n=14), stent (n=8), or combination of these (n=3). Only 3 aneurysms were treated by single-catheter technique. Angiographic results were 66 (91.7%) complete, 5 (6.9%) remnant neck, and 1 (1.4%) incomplete occlusion. Procedural complications included aneurysm rupture (n=1), asymptomatic coil migration to the distal vessel (n=1), and acute thromboembolism (n=10) consisting of 8 asymptomatic and 2 symptomatic events. Treatment-related permanent morbidity and mortality rates were 4.5% and 3.0%, respectively. There was no bleeding on clinical follow-up (mean, 29 months; range, 6-108 months). Follow-up angiographic results (mean, 26 months; range, 6-96 months) in patients included 1 major and 3 minor recanalizations. Conclusion: Coiling of MCA aneurysms could be a technically feasible and clinically effective treatment strategy with acceptable angiographic and clinical outcomes. However, the safety and efficacy of this technique as compared to surgical clipping remains to be ascertained.

• Journal of Korean Neurosurgical Society
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• v.45 no.1
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• pp.11-15
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• 2009

Objective : The aim of study was to review our patient population to determine whether there is a critical aneurysm size at which the incidence of rupture increases and whether there is a correlation between aneurysm size and location. Methods : We reviewed charts and radiological findings (computed tomography (CT) scans, angiograms, CT angiography, magnetic resonance angiography) for all patients operated on for intracranial aneurysms in our hospital between September 2002 and May 2004. Of the 336 aneurysms that were reviewed, measurements were obtained from angiograms for 239 ruptured aneurysms by a neuroradiologist at the time of diagnosis in our hospital. Results : There were 115 male and 221 female patients assessed in this study. The locations of aneurysms were the middle cerebral artery (MCA, 61), anterior communicating artery (ACoA, 66), posterior communicating artery (PCoA, 52), the top of the basilar artery (15), internal carotid artery (ICA) including the cavernous portion (13), anterior choroidal artery (AChA, 7), A1 segment of the anterior cerebral artery (3), A2 segment of the anterior cerebral artery (11), posterior inferior cerebellar artery (PICA, 8), superior cerebellar artery (SCA, 2), P2 segment of the posterior cerebral artery (1), and the vertebral artery (2). The mean diameter of aneurysms was $5.47{\pm}2.536\;mm$ in anterior cerebral artery (ACA), $6.84{\pm}3.941\;mm$ in ICA, $7.09{\pm}3.652\;mm$ in MCA and $6.21{\pm}3.697\;mm$ in vertebrobasilar artery. The ACA aneurysms were smaller than the MCA aneurysms. Aneurysms less than 6 mm in diameter included 37 (60.65%) in patients with aneurysms in the MCA, 43 (65.15%) in patients with aneurysms in the ACoA and 29 (55.76%) in patients with aneurysms in the PCoA. Conclusion : Ruptured aneurysms in the ACA were smaller than those in the MCA. The most prevalent aneurysm size was 3-6 mm in the MCA (55.73%), 3-6 mm in the ACoA (57.57%) and 4-6 mm in the PCoA (42.30%). The more prevalent size of the aneurysm to treat may differ in accordance with the location of the aneurysm.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• v.26 no.1
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• pp.37-45
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• 2024

Objective: To review the characteristics of distal middle cerebral artery (MCA) aneurysm treated by microsurgery, the detailed surgical options, and the clinical result. Methods: We retrospectively reviewed cerebral aneurysm in the M2 and M3 segments of the MCA surgically treated between January 2015 and December 2022. The demographic data, aneurysm-related findings, type of surgical approach, surgical technique, and clinical outcomes of the enrolled patients were analyzed. Results: Sixteen distal MCA aneurysms were treated with microneurosurgery (incidence, 1.0%; female, 12; mean age, 58.1 years; ruptured, three). Twelve aneurysms were in the M2 segment (insular segment), two aneurysms at the M2-M3 junction, and two aneurysms in the M3 segment (opercular segment). Twelve aneurysms were saccular (average size, 4.9 mm; multiplicity, 50%; average aneurysms, 3.0; partially thrombosed, 1; sidewall aneurysm, 2). Three aneurysms were fusiform, of which two were ruptured. Of the ruptured aneurysms, one was a ruptured dissecting aneurysm. The trans-sylvian and trans-sulcal approaches were used in fourteen and two patients, respectively. Neck clipping, wrap clipping, and surgical trapping were performed in twelve, one, and one patient, respectively. Proximal occlusion was performed in one patient. Bypass technique was required in two patients (neck clipping and proximal occlusion). The modified Rankin Score was 6 in the two patients with ruptured aneurysms. The remaining patients did not show further neurological deterioration after microneurosurgery. Conclusions: Distal MCA aneurysms had a high incidence of being diagnosed with multiple other aneurysms and were relatively non-saccular.

• Journal of Korean Neurosurgical Society
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• v.29 no.12
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• pp.1592-1599
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• 2000

Objective : Multiple cerebral aneurysms reportedly account for 14-33% of all cerebral aneurysms. However, multiple separate aneurysms on single parent artery are uncommon. The majority of these are found on middle cerebral artery(MCA). Multiple aneurysms arising from anterior communicating artery(ACoA) are rare. We report 5 cases of multiple aneurysms developed separately on single artery and describe angiographic and operative findings of these lesions. Materials and Methods : Among 127 patients of cerebral aneurysms operated in our hospital, only 5 had multiple aneurysms on single parent artery. Results : Among 5 cases, 4 were diagnosed preoperatively and the only one was found intraoperatively. Two were found on MCA bifurcation, one on M2 and two on ACoA. All separate aneurysms developed on single parent artery were treated successfully with multiple clipping. Conclusion : Multiple cerebral aneurysms, developed separately on single parent artery, are uncommon. Furthermore, those arising from ACoA are very rare. Despite the advanced technology in radiological examinations, multiple cerebral aneurysms may not be detected on preoperative study only. Close proximity or smaller size of the lesion may be responsible for the preoperative false negative angiographic findings.

• Journal of Korean Neurosurgical Society
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• v.53 no.5
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• pp.274-280
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• 2013

Objective : To evaluate the feasibility and clinical and angiographic outcomes of stent-assisted embolization for complex middle cerebral artery (MCA) aneurysms. Methods : The records of 23 consecutive patients with 24 MCA aneurysms, who underwent stent-assisted embolization of the aneurysm, were retrospectively evaluated. Results : Fifteen aneurysms were treated with one stent and 8 were treated using more than two stents (5 a stent-within-a-stent, 1 triple stents, and two Y-stent). Angiographically, complete or near complete occlusion was achieved in 15 aneurysms (65.2%), residual neck in five (21.7%), and residual aneurysm in three (13.1%). Five aneurysms demonstrated thrombosis within the stent during the procedure and hospitalization, and were resolved by intraarterial and intravenous Tirofiban injection. Symptomatic thromboembolic complications were developed in five patients and permanent deficits demonstrated in two patients with modified Rankin Scale 1 and 2, respectively. Treatment-related permanent morbidity and mortality rates were 8.3% and 0% with relatively high complication rate. Angiographic follow-up was available in 17 aneurysms at 6-31 months (mean, 13.2 months) and showed stable or improved in 15 (88.2%) and major and minor recurrence in one, respectively. Conclusion : Complex MCA aneurysms could be treated by stent-assisted coiling and showed lower recanalization rate during mid-term follow-up by effective flow diversion due to various stent-assisted techniques. Our results warrant further study with a longer follow-up period in a larger sample.

• Journal of Korean Neurosurgical Society
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• v.29 no.4
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• pp.521-527
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• 2000

Objective : In general, most of saccular aneurysms arise at arterial divisions, but those arising at unbranched site are rare. These aneurysms might impose neurosurgeons a formidable surgical challenge, due to uncommon features and a difficult surgical technique. Methods : Between the period of Jan. 1996 and Dec. 1998, a total of 110 cases of aneurysms were operated. Among them, five cases of unbranched site aneurysms were retrospectively analyzed through medical records, angiographic and operative findings. Results : The incidence of aneurysms unrelated to arterial branches was 4.5%. All cases presented with subarachnoid hemorrhage(SAH) ; three(60%) were at internal carotid artery(ICA) and two(40%) at middle cerebral artery (MCA). Two had a history of hypertension and three showed atherosclerotic changes in the arterial wall. One ICA and one MCA aneurysms proved to be a blood blister-like aneurysm(BBA) in their shape. Strikingly, a rapid neurological deterioration was shown in two ruptured ICA variants, which resulted in death and another two aneurysms left with morbidity. Conclusion : The preoperative neurological status in most cases was relatively poor compared to that of aneurysms arising at a branched site. Regarding its pathogenesis, atherosclerosis as well as hemodynamic factors may play an important role in formation of these variant aneurysms among various etiological factors. The overall prognosis of unbranched site aneurysms was worse than that of branched site aneurysms. In cases of BBAs, special attention was requisite to handle them during clipping and/or wrapping due to an easy fragile, thin aneurysmal wall.

• Journal of Korean Neurosurgical Society
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• v.47 no.5
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• pp.406-408
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• 2010

Middle cerebral artery (MCA) fusiform aneurysms often have an unfavorable geometry that may limit surgical or endovascular treatment. Herein, we present a case of a fusiform aneurysm of the proximal MCA, which was successfully treated using stent-assisted coil embolization. A 42-year-old man presented with repeated headache and syncope. Five years earlier, a right MCA aneurysm had been treated by aneurismal wrapping. Magnetic resonance images (MRI) revealed a partially-thrombosed proximal MCA aneurysm at the right perisylvian region. Digital subtraction angiography (DSA) revealed a multilobulated fusiform-shaped aneurysm. The patient underwent stent-assisted coil embolization under general anesthesia and symptoms resolved postoperatively. A three-month follow-up angiography revealed no recanalization of the aneurysm and indicated tolerable blood flow through the right MCA, as compared to the preoperative angiography. We suggest that in selected patients, stent-assisted coil embolization of proximal MCA fusiform aneurysms can be an effective treatment modality.